1. Field of the Invention
The present invention concerns a vehicle door operating mechanism, specifically a mechanism for opening and closing a sliding door of a vehicle to provide access to the vehicle through an opening in a wall thereof.
2. Description of the Related Art
It is a general desire among vehicle constructors and designers to provide a sliding door operating mechanism, that includes a minimum of components and a minimum of adjustment places, and that is compact and flexible in its adaption to different vehicle types.
It is also a desire to provide a sliding door operating mechanism that makes opening of a vehicle door impossible during movement of the vehicle.
A further desire is to provide a sliding door operated by a reciprocating power means, such as a pneumatic piston movable within a cylinder, having a travel less than movement of said door between an open and a closed position.
A particular desire is to have access to a sliding door module ready for installation in a vehicle, such door module comprising a frame structure carrying one or more door leaves as well as devices for opening, closing and locking the door blade or blades.
The present invention complies with the desires mentioned by providing a sliding door operating mechanism for a vehicle to provide access to said vehicle through an opening in a wall thereof, including sliding door means and reciprocating power means and transmission means for transmitting movement of said power means to said door means for performing opening, closing and locking movements thereof, which mechanism is characterized by a beam structure carrying said door means, said power means and said transmission means, said beam structure extending across and being accommodated within an upper portion of said opening so as to be slidingly movably driven by said power means between a relatively retracted position within said opening, in which said door means is located in a first plane in a closed position confined within said opening, and a relatively less retracted position, in which said door means is located in a second plane exteriorly of said opening allowing movement of said door means along said second plane.
Apart from the door means, also the reciprocating power means and the transmission means are carried by the beam structure, the power means being of the kind having a housing means and a rod means extendable and retractable relative to the housing means, such as a hydraulic, or, preferably, a pneumatic cylinder with an associated piston and piston rod, or an equivalent, fully mechanical device, such as a device transforming a rotational movement into a linear movement, or any other linear motor. The rod means is connected to the transmission means so as to transfer its movements to the door means, while the housing means is rigidly attached to a sliding member extending in the longitudinal direction of the beam structure and being slidable in that direction relative to the beam structure.
As stated above, in the less retracted position of the beam structure the door means is free to move in its opening direction, and, of course, in its closing direction, operated by the rod means of the power means. When in its fully closed position, however, the rod means cannot move further in its corresponding closing stroke direction. Instead, the housing of the power means moves in an opposite direction, and this movement causes a corresponding longitudinal displacement of the sliding member relative to the beam structure. This longitudinal displacement of the sliding member is transformed into a lateral movement of the beam structure and the door means. This may suitably be accomplished by means of co-operating cam means on the sliding member and stationary cam means, the beam structure being restricted from movement in its longitudinal direction, but guided for movement in its transverse direction, i.e., perpendicularly to the plane of the frame structure and the door means. This transverse movement of the beam structure and the upper portion of the door means is advantageously transferred to the bottom portion of the door means by a link system such that the door means is imparted a controlled, parallel movement.